Electroadhesion grippers are used to secure workpieces to an adhesion surface, for example for transporting the workpieces in industrial production processes such as linked production processes. Generally, at least one electrode is created on an adhesion surface, to which a high voltage is applied such that a strong electric field is generated between the electrode and the environment. A workpiece abutting the adhesion surface is adhered to the adhesion surface when the electric field is switched on, due to electrostatic attraction to opposite charges that are induced in the workpiece. The electrode can be protected from direct contact with the workpiece by a thin insulating film. In the case of a conductive workpiece, two electrodes are typically used, to which an alternating high voltage is applied.
Typical electrodes for electroadhesion grippers have a comb-like structure. The holding force on a workpiece, parallel to the adhesion plane, has a preferred direction; the holding force is considerably smaller in parallel with the teeth of the comb than perpendicular to the teeth. This anisotropy is generally undesirable, such as when the orientation of workpieces to be gripped varies, since the holding force can be very small in unfavorable circumstances, e.g., too small for a secure grip. Typical electroadhesion grippers are disclosed for example in WO 2007/143662 A2, DE 695 23 393 T2 or DE 10 2014 215 333 B3.